/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.carbondata.core.datastorage.store.columnar;

import java.util.Arrays;

public final class UnBlockIndexer {

  private UnBlockIndexer() {

  }

  public static int[] uncompressIndex(int[] indexData, int[] indexMap) {
    int actualSize = indexData.length;
    for (int i = 0; i < indexMap.length; i++) {
      actualSize += indexData[indexMap[i] + 1] - indexData[indexMap[i]] - 1;
    }
    int[] indexes = new int[actualSize];
    int k = 0;
    for (int i = 0; i < indexData.length; i++) {
      int index = Arrays.binarySearch(indexMap, i);
      if (index > -1) {
        for (int j = indexData[indexMap[index]]; j <= indexData[indexMap[index] + 1]; j++) {
          indexes[k] = j;
          k++;
        }
        i++;
      } else {
        indexes[k] = indexData[i];
        k++;
      }
    }
    return indexes;
  }

  public static byte[] uncompressData(byte[] data, int[] index, int keyLen) {
    if (index.length < 1) {
      return data;
    }
    int numberOfCopy = 0;
    int actualSize = 0;
    int srcPos = 0;
    int destPos = 0;
    for (int i = 1; i < index.length; i += 2) {
      actualSize += index[i];
    }
    byte[] uncompressedData = new byte[actualSize * keyLen];
    int picIndex = 0;
    for (int i = 0; i < data.length; i += keyLen) {
      numberOfCopy = index[picIndex * 2 + 1];
      picIndex++;
      for (int j = 0; j < numberOfCopy; j++) {
        System.arraycopy(data, srcPos, uncompressedData, destPos, keyLen);
        destPos += keyLen;
      }
      srcPos += keyLen;
    }
    return uncompressedData;
  }

}
